1. Field of the Invention
The present invention relates to an automotive air conditioning apparatus, especially, an automotive air conditioning apparatus for cooling a passenger room by use of a Stirling refrigerator.
2. Description of the Related Art
A Stirling refrigerator is operated to repeat an isothermal compression, an isochoric cooling, an isothermal expansion and an isochoric heating of an operating gas such as air and helium gas. The operating gas absorbs heat at the time of the isothermal expansion, and the operating gas is heated at the time of the isothermal compression. This is disclosed in REITO Vol. 63, No. 733.
It is known that the above conventional Stirling refrigerator is installed into a domestic chilling unit. This is disclosed in Japanese Unexamined Patent Publication No. 208459/1990.
When the Stirling refrigerator is used for cooling the passenger room, it requires another radiator in addition to a radiator for cooling the vehicle engine since a refrigerant circulated in a radiating portion requires an individual radiator. Thus, it is difficult to lighten the vehicle weight.